Automatic electric controller.



B. W. SWEET.

AUTOMATIC ELECTRIC CONTROLLER. APPLICATIQN FILED APR.21.1913.

2 SHEETS-SHEET I.

ZUfzZzze-ns airzz z/ezzzar- Patented Apr. 24, 1917.

B. W. SWEET. AUTOMATIC ELECTRIC CONTROLLER.

. I APPLICATION FILED APR.2I. 1913. 1,223,530. Patented Apr. 24,1917.

2 SHEETSSHEET 2.

UNITED STATES PATENT OFFICE.

BUFTOII W. SWEET, 0F CLEVELAND, OHIO, ASSIGNOB, BY MESNE ASSIGNMENTS, TO THE VAN DORN ELECTRIC TOOL COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

AUTOMATIC ELECTRIC CONTROLLER.

Application filed Apri121, 1913. Serial No. 762,451.

To all whom z't may concern:

Be it known that I, BURTON W. SWEET, a citizen of the United States, and a resident of Cleveland, county of Cuyahoga, and State of Ohio, have invented a new and useful Im- 'irovement in Automatic Electric Controllers, of which the following is a specification, the principle of the invention being herein explained and the best mode in which 1 have contemplated applying that principle, so as to distinguish it from other inventions, The subject of the present invention is an improved controller adapted to automatically cut into a translating circuit a resistance upon a sudden increase in the current which is flowing through the circuit. To the accomplishment of the foregoing and related ends, said invention then consists of the means hereinafter fully described and particularly pointed out in the claims.

The annexed drawing'and the following description set forth in detail certain mechanism embodying the invention, such disclosed means constituting, however, but one of various mechanical forms in which the principle of the invention may be used.

In said annexed drawings:

I igure 1 is a front elevation of the device in its normal position; Figure 2 1s a section on the line 2-2, Figure 1; Figure dis a view similar to Figure 1 but showing the device at the instant of breaking the circuit and Figure 4 is a diagram illustrating the wiring connections. Referring to Figure l, the general connections will be readily seen, there being a motor or suitable translating device 1 in a trans lating circuit connected by line wires 2 and 3 to a suitable source of current not'shown, such circuit including an electro-magnet 4 and also a resistance 5 which of course normally receives but a small portion of the current flowing through the circuit, the greater part of the current flowing through the solenoid 4 and through the wires 6 to -'the switch mechanism which is controlled by the movement of the armature of the solenoidl A separate switch 7 is provided .for manual operation andmay be disposed at any convenient point in the circuit.

The construction of the controller itself is best seen in Figure 1 the solenoid being suitably mounted upon a plate 8 which will preferably be attached to a wall as the controller can most conveniently be fixed and the plate there is also mounted the resistance coil 5 which is connected, as indicated in Figure 3, with the wire 9 leading from the solenoid. The armature of the solenoid is in the form of a plunger 1.0 having attached to its outer end a yoke 11, such yoke being formed with two sockets 12 slidably engaging upon guide bars 13 which are fixed in similar sockets 11 attached to a stationary yoke 15 mounted on the other end of the solenoid and attached to the plate 8. Upon the guide bars 13 there are mounted coiled springs 16, the tension of which is controlled by means of locking nuts 25 adjustably mounted upon the guide bars at the lower ends of the same.

Upon the fixed yoke 15 there is mounted a resilient arm 18 hearing adjustably a contact member 19 which is adapted to engage a similar contact member 20 similarly held device, the current will flow through the solenoid and will then flow directly through the switch mechanism consisting of the two contact arms to the motor, a very small portion of the current flowing through the resistance coil. Upon a sudden increase in the current, the solenoid will operate to draw the plunger inwardly, but the contact arms 18 and 21 will remain in contact by reason of the resilience of the contact arm 18, until the plunger has moved through a predetermined range of movement, when the resilient arm 18 will have reached its normal position and the arm 21 will then be moved suddenly away from this aimfthus rapidly breaking the circuit. The movement of the plunger is at first slow by reason of the usual gradual increase in the current, and also on ac- Patented Apr. 24, 191 '7.

in. an arm 21 attached to the yoke 11 of the mounted in the resilient arm, the limiting position of this arm can be varied, or as it may be] termed, the available resilience can be increased or diminished by adjustment of the set-screw in or out thus controlling in another way the point of breaking of the circuit and the speed of breaking.

. By the expression cutting into the translating circuit is meant not the actual switching in of a resistance previously out of the circuit but the connecting of the re sistance in the circuit in an eflectual manner,

since the resistance coil is of course continuously in circuit but] is ineffective so long as the current is flowing through the direct connection fromthe solenoid to the translating device. Attention is called to the means for accurate adjustment of the controller to operate under various desired conditions, which permits of securing a very sharp break upon any desired increase in current within of course the limits of the adjustment.

Other modes of applying the principle of my invention may be employed instead of the one explained, change being made as regards the mechanism herein disclosed, provided the means stated by any of the following claims or the equivalent of such stated claims be employed.

'I. therefore particularly point out and distinctly claim as my invention 1. Inan automatic electro magnetic switch the combination of an electro-magnet; an armature actuated by said magnet; switch means operable by movement of said armature over a predetermined distance;

said switch means including .two resilient contact carrying arms; means for adjusting position of one of said resilient arms to vary the amount of armature movement required to operate said switch means; and other ,meansfadirpted to vary the sensitiveness of said electro-magnet to current increase in said circuit.

2..In an automatic electro -'magnetic switch, the combination of an electro-magnet; an armature actuated by said magnet; switch means operable by movement of said armature over a predetermined distance, saidswitch'means including two resilient contact carrying arms; meansfor adjusting the position of one of said resilient arms to vary the amount of armature movement required to operate said switch means; and other means adapted to vary the sensitiveness of said electro-magnet to current increase in said circuit, said other means consistin of adjustable coil springs adapted to resist movement of said armature;

3. In an automatic electro magnetic switch the combination of an electro-magnet; an armature actuated by the same; switch means operated by movement of said armature; guide bars slidably engaged by said armature; springs mounted about said bars in contact with said armature; and means adapted to adjust the tension of said springs to vary the resistance to movement of said armature.

4:. In an automatic -electro magnetic switch the combination of an electro-magnet; an armature actuated by the same; switch means operated by movement of said armature; guide bars slidably engaged by said armature; springs mounted about said bars in contact with said armature; and adj usting nuts attachedto said bars and adapted to compress said springs to increase the resistance to movement of said armature.

5. In an electro-magnetic switch the combination of an electro-magnet; an armature actuated by the same; a yoke attached to the outer end of said armature and movable BURTON W. SWEET.

Attested by- H. B. FAY, ANNA L. GILL. 

